Senior Scientist, LNP Formulations

Flagship Pioneering, Inc.•Cambridge, MA

1d•$126,000 - $181,500

About The Position

Serif Biomedicines is seeking a highly motivated Senior Scientist II with deep expertise in lipid chemistry to drive the design of novel ionizable lipids and next-generation lipid nanoparticle (LNP) formulations for nucleic acid delivery. The role focuses on rational design and synthesis of ionizable lipids, optimizing LNP molar compositions, and preparing formulations to screen and benchmark new lipids. The position offers a chemist the opportunity to move molecules rapidly from the bench into functional LNPs, working at the intersection of medicinal and organic chemistry, formulation science, and delivery biology. The Senior Scientist is expected to work independently, influence cross-functional program direction, identify innovative solutions, mentor junior scientists, and contribute to scientific strategy through internal leadership and external scientific engagement. Serif Biomedicines is an early-stage biotechnology company developing a novel gene therapy approach for currently untreatable diseases. The position is located in Cambridge, Massachusetts. The stated salary range is $126,000–$181,500, with compensation dependent on qualifications, skills, competencies, and experience. The company offers healthcare coverage, an annual incentive program, retirement benefits, and other benefits.

Requirements

PhD in Organic Chemistry, Medicinal Chemistry, Chemical Biology, Pharmaceutical Sciences, or a related field with 5 or more years of relevant industry experience; alternatively, an M.S. with 8 or more years of experience.
Strong background in multi-step organic synthesis, purification, and structural characterization, ideally involving lipids, amphiphiles, or other delivery materials.
Hands-on experience with LNP formulation, such as microfluidic mixing or nanoprecipitation, and understanding of how lipid structure and molar composition affect potency, stability, and tolerability.
Experience designing and conducting formulation screens, including characterization by DLS, encapsulation assays, and pKa determination.
Demonstrated ability to design experiments, analyze data, and solve complex technical problems.
Strong communication and collaboration skills, and experience mentoring junior scientists.

Nice To Haves

Experience with nucleic acid delivery, including mRNA, DNA, or siRNA, is highly preferred.
Familiarity with lipid analytics such as NMR, LC-MS, and HPLC-CAD/ELSD.
Familiarity with computational or data-driven approaches to lipid design.
A record of innovation, such as publications or patents.

Responsibilities

Design and synthesize novel ionizable lipids, including head-group, linker, and tail variants, using structure-activity relationships and profiles for pKa, biodegradability, and tolerability to guide design.
Lead the design of LNP molar compositions, optimizing ratios of ionizable lipid, helper lipid, cholesterol, and PEG-lipid, and exploring alternative or novel excipients for potency, stability, and tolerability.
Prepare small-scale LNP formulations using microfluidic or other mixing methods to enable medium- to high-throughput screening of new lipids and compositions.
Plan and conduct formulation screening studies, define critical formulation parameters, and build structure-property relationships across lipid libraries.
Characterize lipids and LNPs using appropriate analytical methods, including NMR, LC-MS, HPLC with CAD/ELSD, DLS, encapsulation assays, and apparent pKa assays; ensure lipid identity and purity.
Collaborate with biology, analytical, process development, and external partners to evaluate lead formulations in vitro and in vivo and incorporate results into subsequent design cycles.
Analyze and interpret experimental data, maintain detailed documentation, and communicate findings to internal stakeholders.
Mentor junior scientists and contribute to delivery-platform scientific strategy and intellectual property position.
Stay current with advances in ionizable lipid chemistry, LNP technologies, and nucleic acid delivery.